hi all,
can anybody give interface to create supercolumn in supercolumn and fill the
data...in cassandra with example
Thanks
bujji
> can anybody give interface to create supercolumn in supercolumn and fill the
> data...in cassandra with example
That would be hard since you cannot have supercolumns in supercolumns.
Supercolumns give you one more level of nesting but that's it.
--
Sylvain
Sure. Please create a jira ticket
(https://issues.apache.org/jira/browse/CASSANDRA) and attach the files
you wish to contribute. One of the committers (probably myself) will
review them and decide how to integrate them into the project.
If it's not too much trouble, an ant build script would be
Pelops is a new high quality Java client library for Cassandra.
It has a design that:
* reveals the full power of Cassandra through an elegant "Mutator and
Selector" paradigm
* generates better, cleaner, less bug prone code
* reduces the learning curve for new users
* drives rapid application deve
Sounds nice. Can you say something about the scales at which you've used
this library? Both write and read load? Size of clusters and size of data?
Ian
On Fri, Jun 11, 2010 at 9:41 AM, Dominic Williams <
thedwilli...@googlemail.com> wrote:
> Pelops is a new high quality Java client library fo
One of our cassandra nodes suddenly crashed, then the other 2...
Exceptions found in the system.log are attached below.
Any ideas? Does it mean that we've got some bad data running around in the
cluster?
Many thanks
The exeption on the node that crashed first was like
ERROR [RESPONSE-STAGE:669] 20
Hi good question.
The scalability of Pelops is dependent on Cassandra, not the library itself.
The library aims to provide an more effective access layer on top of the
Thrift API.
The library does perform connection pooling, and you can control the size of
the pool and other parameters using a po
li wei yahoo.com> writes:
>
> Thanks you very much, Per!
>
> - Original Message
> From: Per Olesen trifork.com>
> To: "user cassandra.apache.org" cassandra.apache.org>
> Sent: Wed, June 9, 2010 4:02:52 PM
> Subject: Re: Quick help on Cassandra please: cluster access and performanc
Dominic,
I like the API; reads clearly and fairly intuitive.
I think Ian was asking about what large-scale production deployments Pelops
has been deployed in that you could speak to -- he's trying to get a
confidence index and I am interested as well ;)
Best,
Riyad
On Fri, Jun 11, 2010 at 7:04
Ran Tavory gmail.com> writes:
>
> I can't say exactly how much memory is the correct amount, but surely 1G is
very little. By replicating 3 times your cluster now makes 3 times more work
than it used to do, both on reads and on writes while the readers/writers
continue hammering it the same pace
Caribbean410,
This comes up on the Redis list alot as well -- what you are actually
measuring is the client sending a network connection to the Cas server and
it replying -- so the performance numbers you are getting can easily be 70%
network wait time and not necessarily hardcore read/write serve
li wei yahoo.com> writes:
>
> Thanks you very much, Per!
>
> - Original Message
> From: Per Olesen trifork.com>
> To: "user cassandra.apache.org" cassandra.apache.org>
> Sent: Wed, June 9, 2010 4:02:52 PM
> Subject: Re: Quick help on Cassandra please: cluster access and performance
On Fri, Jun 11, 2010 at 10:14, Julie wrote:
> Ran Tavory gmail.com> writes:
>
>>
>> I can't say exactly how much memory is the correct amount, but surely 1G is
> very little. By replicating 3 times your cluster now makes 3 times more work
> than it used to do, both on reads and on writes while th
Jonathan, while I agree with you re: this being an unusual load for the
system, it is interesting that he's found at least one use-case where
Cassandra is CPU-bound, not IO-bound. I'd definitely be interested in
learning what his critical path is and seeing if there's some low-hanging
fruit that ma
Would it be reasonable to have (possibly configurable) caps on the maximum size
of any internal Cassandra queues that are directly populated by client
requests? I understand this might mean sometimes breaking the API contract for
writers using CL.ZERO by blocking on those calls, but on the other
Thanks Riyad.
Right now I am just testing Cassandra on single node. The server and client
are running on the same machine. I tried the read test again on two
machines, on one machine the cpu usage is around 30% most of the time and
another is 90%.
Pelops is one way to access Cassandra, there are
What is the best way to determine the timestamp of a row (ie. the most
recent time when any of the columns of a row were modified).
Correct me if I am wrong, but I beleive a row does not have a timestamp,
only individual columns have timestamps.
So for instance if I need to know when a row was la
> Correct me if I am wrong, but I beleive a row does not have a timestamp,
> only individual columns have timestamps.
You are correct
> So for instance if I need to know when a row was last modified, would I have
> to perform a get_slice and get all columns pertaining to that row, and then
> iter
Hello,
I was browsing the docs for the RackAware replication strategy and saw this on
the wiki:
"RackAwareStrategy: replica 2 is placed in the first node along the ring the
belongs in another data center than the first; the remaining N-2 replicas, if
any, are placed on the first nodes along the
We give you enough rope to hang yourself. Don't use ZERO if that's
not what you want. :)
On Fri, Jun 11, 2010 at 9:23 AM, William Ashley wrote:
> Would it be reasonable to have (possibly configurable) caps on the maximum
> size of any internal Cassandra queues that are directly populated by cli
I'm not sure what parts of these you think are in conflict.
On Fri, Jun 11, 2010 at 10:34 AM, Blew, Aaron wrote:
> Hello,
> I was browsing the docs for the RackAware replication strategy and saw this
> on the wiki:
>
> "RackAwareStrategy: replica 2 is placed in the first node along the ring the
you need to look at cfstats to see what the latency is internal to
cassandra, vs what your client is introducing
then you should probably read the comments in the configuration file
about caching
On Fri, Jun 11, 2010 at 9:38 AM, Caribbean410 wrote:
>
> Thanks Riyad.
>
> Right now I am just testi
The first text says the N-2 replicas are placed in the same rack while the
second text indicates that the N-2 replicas will be placed in different racks.
Am I missing something?
-Aaron
---
Aaron Blew -
Sr. Infrastructure Engineer | The Automator
iovation - The Power of Reputation™
aaron.b...@io
Hello Jonathan,
El 08/06/2010, a las 19:15, Jonathan Ellis escribió:
> Sounds like you had some bad hardware take down your index files.
> (Cassandra fsyncs them after writing them and before renaming them to
> being live, so if it's missing pieces then it's always been hardware
> at fault that I
You're mis-parsing the first. It says "place one replica in a
different datacenter, and the others on different racks in the same
one," where the antecedent of "one" is "datacenter," not rack.
On Fri, Jun 11, 2010 at 11:09 AM, Blew, Aaron wrote:
> The first text says the N-2 replicas are placed
Hmm. That seems to be saying that sstable2json is using the index
file, and erroring out there the same way the Cassandra server does.
So it doesn't necessarily mean the data files are corrupt.
On Fri, Jun 11, 2010 at 11:20 AM, Lucas Di Pentima
wrote:
> Hello Jonathan,
>
> El 08/06/2010, a las 1
I think it would be a good exercise to know what the CPU bottleneck is on the
write path. The fact that Cassandra optimizes disk I/O for writes would only go
so far if the CPU becomes a big bottleneck on continuous writes. I am fairly
new to Java ecosystem performance profiling but I would give
That makes sense. It still seems to conflict with what's stated in the
wiki:
"...the remaining N-2 replicas, if any, are placed on the first nodes along
the ring in the *same* rack as the first"
-Aaron
On Fri, Jun 11, 2010 at 11:20 AM, Jonathan Ellis wrote:
> You're mis-parsing the first. I
Hello, Is the snapshot location somewhere configurable with 0.62 (There is a
ticket
http://www.mail-archive.com/cassandra-comm...@incubator.apache.org/msg09432.html
but seems to be not implemented yet)? Tx.
Gary fwiw I get oom with Cl one quite commonly if I'm not careful with my
writes
On Jun 11, 2010 8:48 PM, "Jonathan Ellis" wrote:
We give you enough rope to hang yourself. Don't use ZERO if that's
not what you want. :)
On Fri, Jun 11, 2010 at 9:23 AM, William Ashley wrote:
> Would it be reas
Then the wiki is incorrect.
On Fri, Jun 11, 2010 at 11:33 AM, Aaron Blew wrote:
> That makes sense. It still seems to conflict with what's stated in the
> wiki:
> "...the remaining N-2 replicas, if any, are placed on the first nodes along
> the ring in the *same* rack as the first"
> -Aaron
>
>
That ticket was closed wontfix because it doesn't make sense to make
this configurable, which would allow users to shoot themselves in the
foot very easily (by mis-configuring snapshot location to a different
volume) for no real benefit.
On Fri, Jun 11, 2010 at 11:37 AM, Stephan Pfammatter
wrote:
yes, it is expected that writes are cpu-bound.
On Fri, Jun 11, 2010 at 11:29 AM, Rishi Bhardwaj wrote:
> I think it would be a good exercise to know what the CPU bottleneck is on
> the write path. The fact that Cassandra optimizes disk I/O for writes would
> only go so far if the CPU becomes a bi
So I have setup some test with Cassandra (with OCM). Though not very
impressed with the single read speeds , I have observed that it does scale
very well even with numerous number of concurrent readers .. However I have
observed that no matter what I do , I am somehow limitted to around 4 ms of
rea
Thanks, I just tried apache-cassandra-2010-06-11_12-30-33 (hudson 462) but my
tests ares still reporting a leak (though not as bad), I do the following (ruby
tests using cassandra_object/cassandra, but you should be able to get the idea):
should "not leak file descriptors" do
cassa
Hi Everyone
I am wondering why default visibility constructors were added to each of the
*Type classes in the db.marshal package? If I'm understanding right, this
breaks the CLI.
Explanation:
This is the original UTF8Type class from 0.6.2, which worked:
import java.io.UnsupportedEncodingExcepti
you're probably reading more or larger columns from that CF.
I would consider using row cache on that CF and on Deployment based on
the query volumes seen here.
On Fri, Jun 11, 2010 at 12:32 PM, Nazario Parsacala
wrote:
> So I have setup some test with Cassandra (with OCM). Though not very
> imp
Hi All,
I'd like to start using trunk for something real, but am concerned about
stability of the data format. That is, will I be able to upgrade a running
system to a newer version of trunk and eventually to the 7.0 release, or are
there any changes planned to the format of the data stored on
Can we configure/optimize the write path to lower CPU bound and improve
performance? I am wondering if I should investigate and see what is eating up
so much of CPU (memory/data copying? bloom filters? etc.). Would this be a
worthwhile investigation to see if we can improve on things or is there
This is the cfstats. Right now I use three thread to read 200k records. I
only use Keyspace1 and Column family Standard2. For other unused column
families, do I need to comment them out in storage configure file? The
latency is 0.2576ms per records, is this a regular number (we are reading
from ssd
The types should be singletons. Jeremy has submitted a patch fixing the CLI.
On Fri, Jun 11, 2010 at 2:01 PM, Eben Hewitt wrote:
> Hi Everyone
> I am wondering why default visibility constructors were added to each of the
> *Type classes in the db.marshal package? If I'm understanding right, thi
it goes up by exactly 2000, which is the number of loop iterations
exactly? are you sure this isn't just counting your open sockets?
On Fri, Jun 11, 2010 at 1:53 PM, Matthew Conway wrote:
> Thanks, I just tried apache-cassandra-2010-06-11_12-30-33 (hudson 462) but my
> tests ares still reportin
If you're comfortable following comm...@cassandra.apache.org, it
should be pretty obvious which changes are going to break things
temporarily or require a commitlog drain. Otherwise, we recommend
sticking with the stable branch until a beta is released.
On Fri, Jun 11, 2010 at 2:24 PM, Matthew Co
On Fri, Jun 11, 2010 at 1:23 PM, Jonathan Ellis wrote:
> Hmm. That seems to be saying that sstable2json is using the index
> file, and erroring out there the same way the Cassandra server does.
> So it doesn't necessarily mean the data files are corrupt.
I believe you can confirm this with sst
Other way around: sstablekeys _only_ reads the index.
On Fri, Jun 11, 2010 at 4:51 PM, Brandon Williams wrote:
> On Fri, Jun 11, 2010 at 1:23 PM, Jonathan Ellis wrote:
>>
>> Hmm. That seems to be saying that sstable2json is using the index
>> file, and erroring out there the same way the Cassan
I remove some unnecessary column family and change the size of rowcache and
keycache, now the latency changes from 0.25ms to 0.09ms. In essence
0.09ms*200k=18s. I don't know why it takes more than 400s total. Here is the
client code and cfstats. There are not many operations here, why is the
extra
Jassandra is used here:
Map> map = criteria.select();
The select here basically is a call to Thrift API: get_range_slices
From: Caribbean410 [mailto:caribbean...@gmail.com]
Sent: Saturday, June 12, 2010 8:00 AM
To: user@cassandra.apache.org
Subject: Re: read operation is slow
I
Hi, do you mean this one should not introduce much extra delay? To read a
record, I need select here, not sure where the extra delay comes from.
On Fri, Jun 11, 2010 at 5:29 PM, Dop Sun wrote:
> Jassandra is used here:
>
>
>
> Map> map = criteria.select();
>
>
>
> The select here basically is a
You mean after you "I remove some unnecessary column family and change the
size of rowcache and keycache, now the latency changes from 0.25ms to
0.09ms. In essence 0.09ms*200k=18s.", it still takes 400 seconds to
returning?
From: Caribbean410 [mailto:caribbean...@gmail.com]
Sent: Saturday, Jun
Hi, previously it is 438s. Now it is 399s. Still large.
On Fri, Jun 11, 2010 at 5:56 PM, Dop Sun wrote:
> You mean after you “I remove some unnecessary column family and change
> the size of rowcache and keycache, now the latency changes from 0.25ms to
> 0.09ms. In essence 0.09ms*200k=18s.”, it
And also, you are only select 1 key and 10 columns?
criteria.keyList(Lists.newArrayList(userName)).columnRange(nameFirst,
nameFirst, 10);
Then, if you have 200k keys, you have 200k Thrift calls. If this is the
case, you may need to optimize the way you do the query (to combine multiple
key
Thanks for the suggestion. For the test case, it is 1 key and 1 column. I
once changed 10 to 1, as I remember there is no much difference.
I have 200k keys and each key is randomly generated. I will try the
optimized query next week. But maybe you still have to face the case that
each time a cl
When using cassandra with django, can you still use the rapid development
freatures of django w/cassandra or are you basically just using the
framework but the models and ORM features are up to you to implement since
you are using cassandra.
There's no direct support for cassandra in django, but there are a
couple starts.
http://www.allbuttonspressed.com/projects/django-nonrel
http://github.com/enki/tragedy
http://code.djangoproject.com/wiki/SummerOfCode2010
All of the features which Django has and which build on the ORM are
out, of
I see, well I am new to python + django so I wasn't sure what I really meant
:)
So basically I am using django for its framework related features, but
excluding the ORM/autogen admin pages.
That's reasonable and understable thanks.
On Fri, Jun 11, 2010 at 10:38 PM, Jeremy Dunck wrote:
> There'
sounds like most of the latency is in your client code, or waiting for
the network
On Fri, Jun 11, 2010 at 6:02 PM, Caribbean410 wrote:
> Hi, previously it is 438s. Now it is 399s. Still large.
>
> On Fri, Jun 11, 2010 at 5:56 PM, Dop Sun wrote:
>>
>> You mean after you “I remove some unnecessar
I think you'll find the django-users mailing list pretty helpful. If
you'd like to contribute use-cases to the GSoC nonrel work, that'd be
django-developers.
Good luck. :-)
On Fri, Jun 11, 2010 at 9:43 PM, S Ahmed wrote:
> I see, well I am new to python + django so I wasn't sure what I really
Many files are corrupted when our cassandra is update to 0.6.2
COMPACTION-POOL is down caused by the following error.
and some nodes can NOT startup because of this error.
Is it caused by the issue CASSANDRA-1169? The node got the wrong or corrupted
stream file?
ERROR [COMPACTION-POOL:1] 2010-06
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